A high pressure fluid is often expanded, i.e. reduced in pressure, through a turbine to extract useful energy from the fluid and thus to produce work. The high pressure fluid enters the turbine and passes through a plurality of passages defined by turbine blades which are mounted on an impeller hub which in turn is mounted on a shaft. The fluid enters the blade passages and causes rotation of the impeller and ultimately leads to the recovery of energy and to the production of work from the spinning shaft.
It is desirable to operate the expansion turbine with as high an efficiency as possible. Since turboexpanders generally handle large volumes of fluid, even a small increase in turbine efficiency will have a significant impact on operating results.
Accordingly, it is an object of this invention to provide an improved method for operating a turboexpander to achieve increased efficiency over that attainable with known operating methods.
It is another object of this invention to provide a high efficiency turboexpander having increased efficiency over that attainable with known turboexpanders.